Mortality and morbidity are classic indicators of a population's health. In the case of Amedcan Indians/Alaska Natives (AI/ANs), such statistics show that the past century was one of tremendous progress--especially in the prevention and treatment of infectious diseases. Nonetheless, in the most recent report on AI health trends, the life expectancy o f A ItANs remains 4.7 years Iess than t hat o f t he U .S. population. Infectious diseases h ave been replaced by chronic conditions with 3 of the 4 leading causes of death among AI/ANs being of a chronic nature heart disease, cancer, and diabetes (with injuries the remaining category). Thus, AllAN health care has moved from a focus on acute care of infectious diseases to long-term management of disease with their physical and psychological concomitants. As a consequence, the need for reliable and valid assessments of patient perceptions of the impact of such diseases on their well-being increases. Such scales have considerable promise as outcome measures for clinical trials and other interventions. Finally, if reliable and valid, they have the potential for becoming important population descriptors as we attempt to better address health disparities. The Medical Outcomes Study Short Form 36 Health Survey (SF-36) is one of the most widely used general measures of health-related quality of life (HRQoL). Preliminary psychometric analyses in AI samples have indicated that, although this measure has generally acceptable properties, an assumption that it functions equivalently to others in the U.S. is unwarranted. In order to further our understanding of this general measure of HRQoL, we propose pairing secondary analyses with primary ethnographic data collection to address the following aims. Specific Aim 1: Using Item-Response Theory (IRT), to understand whether 2 AI samples choose among response options in a comparable manner to a national sample. Specific Aim 2: Using ethnographic methods, to review the SF-36 and our analyses with AI patients and their providers to better understand their interpretations of the SF-36 items and to determine whether additional items are required to assess HRQoL in these populations. Specific Aim 3: Based on the proposed work and that already in progress, to formulate recommendations for use of the SF-36 and related measures in AI clinical and epidemiological settings. The proposed a nalyses w ill further refine t he S F-36 for use among A I/AN populations. Furthermore, t he p aidng o f qualitative and quantitative methods promises to enhance our understandings of how HRQoL is conceptualized in these populations.